Bug 1746430: URLClassifier cleanup r=dimi

Differential Revision: https://phabricator.services.mozilla.com/D134029

toolkit/components/url-classifier/nsUrlClassifierPrefixSet.cpp

@@ -447,6 +447,8 @@ nsresult nsUrlClassifierPrefixSet::LoadPrefixes(nsCOMPtr<nsIInputStream>& in) {
 
 uint32_t nsUrlClassifierPrefixSet::CalculatePreallocateSize() const {
   uint32_t fileSize = 4 * sizeof(uint32_t);
+  MutexAutoLock lock(mLock);
+
   MOZ_RELEASE_ASSERT(mTotalPrefixes >= mIndexPrefixes.Length());
   uint32_t deltas = mTotalPrefixes - mIndexPrefixes.Length();
   fileSize += mIndexPrefixes.Length() * sizeof(uint32_t);

toolkit/components/url-classifier/nsUrlClassifierPrefixSet.h

@@ -79,7 +79,7 @@ class nsUrlClassifierPrefixSet final : public nsIUrlClassifierPrefixSet {
   // how many prefixes we have.
   uint32_t mTotalPrefixes;
 
-  nsCString mName;
+  nsCString mName;  // Set in Init() only
   mozilla::CorruptionCanary mCanary;
 };